I think if I was to put a mobile base under a jointer that size I would want 4 swivel casters so it could be pushed up against a wall easily. The 2 fixed 2 swivel design used by most table saws works because one side doesn't have a extension table so you can jockey it to get it close. But with tables on both sides I'm thinking that tucking it nice and close to a wall would be extremely hard.